1、Designation: D7133 16Standard Test Method forPolyurethane Raw Materials: Instrumental Measurement ofTristimulus CIELAB Color and Yellowness Index of Liquids1This standard is issued under the fixed designation D7133; the number immediately following the designation indicates the year oforiginal adopt
2、ion or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method provides an instrumental method formeasuring the CIELAB
3、 color and Yellowness Index (YI) ofliquid polyurethane raw materials. The CIELAB and YI resultsare derived from mathematical manipulation of CIE tristimulusvalues in accordance with Practices E308 and E313, respec-tively.1.2 The values stated in SI units are to be regarded asstandard. The values giv
4、en in parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to
5、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE 1There is no known ISO equivalent to this standard.2. Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1193 Specification for Reagent WaterE180
6、 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals (Withdrawn 2009)3E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE313 Practice for Calculating Yellowness and WhitenessIndices
7、from Instrumentally Measured Color CoordinatesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsFor definitions of terms that appear in thistest method, refer to Terminologies E284, D883, and theterminology section of Practic
8、e E308.4. Summary of Test Method4.1 The color of the total transmitted light is measured by aspectrophotometer in CIE tristimulus values under CIE stan-dard illuminant D65 and CIE 1964 supplementary standardobserver commonly called the 10 standard observer. Thesevalues are then converted by the appr
9、opriate equations to theCIELAB color scale and the Yellowness Index. L*a*b* and YIvalues are reported.5. Significance and Use5.1 CIELAB is a visual-based scale that is used to specifycolor and set color tolerances for the polyurethane industry.5.2 Yellowness Index specifies the degree of departure o
10、fthe sample from colorless towards yellow. This index is onlysuitable for clear liquids with degrees of saturation in yellow(dominant transmission wavelength in the 570 to 580 nmrange). It is used to set tolerances for appropriate polyurethaneraw materials.5.3 This test method does not include provi
11、sions for mate-rials with fluorescence or visible haze (usually greater than 5 %haze).5.4 Before proceeding with this test method, make referenceto the specification of the material being tested. Any testspecimen preparation, conditioning, dimensions, or testingparameters or combination thereof, cov
12、ered in the materialsspecification shall take precedence over those mentioned in thistest method. If there are no material specifications, then thedefault conditions apply.6. Interferences6.1 This test method is to be used to compare samples onlywhen they are measured under the same conditions.6.1.1
13、 The medium in the cuvette used during standardiza-tion of the instrument will have an effect on the measured1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.22 on Cellular Materials -Plastics and Elastomers.Current edi
14、tion approved Sept. 1, 2016. Published September 2016. Originallyapproved in 2005. Last previous edition approved in 2011 as D7133 - 11.DOI:10.1520/D7133-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AS
15、TMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO
16、 Box C700, West Conshohocken, PA 19428-2959. United States1results. Light mineral oil is recommended, however, distilledwater is a suitable substitute but a note of the substitution mustbe included in any report of the results.6.1.2 The temperature of the sample is also expected toaffect the results
17、 obtained.7. Apparatus7.1 InstrumentA hemispherical geometry (integratingsphere) spectrophotometer capable of total transmission(TTRAN) CIE tristimulus measurement through a cuvette.TTRAN includes both the regularly transmitted portion and thediffused portion of the incident light. The instrument mu
18、st becapable of converting CIE XYZ tristimulus values to theCIELAB color scale as defined in Practice E308 using CIED65 standard illuminant and 10 standard observer. Theinstrument must also be capable of converting CIE XYZtristimulus values to the Yellowness Index value defined inPractice E313 using
19、 CIE D65 standard illuminant and 10standard observer. The instrument is to meet the manufactur-ers requirements for calibration. For highly transparentsamples, such as the polyols in Tables 1 and 2, spectropho-tometers or tristimulus colorimeters without a spherical geom-etry are acceptable for use
20、with equivalent results.7.2 Sample CuvettesThe cuvette must have a 20 6 0.06mm pathlength. The entrance and exit windows shall beparallel, colorless, clear and unaffected by the material beinganalyzed. The optical properties of the cuvette used duringstandardization of the instrument and the cuvette
21、 used formeasuring samples (if not the same cuvette) must be matched.This is determined by proving that the variation, if any, in thedifferent cuvettes used do not affect the measured value of astandard sample. Glass or plastic cuvettes are both acceptable.8. Reagents8.1 Mineral OilColorless NF or F
22、CC grade light mineraloil.8.2 Distilled WaterColorless distilled water conforming toType IV of Specification D1193.9. Sampling and Test Specs and Units9.1 Test samples are to be homogeneous and representativeof the liquid being tested.9.2 Do not touch the entrance and exit windows of thecuvette thro
23、ugh which incident and transmitted light will passexcept to clean them.9.3 The CIELAB values, L*, a*, and b*, have no unitsassociated with them.9.4 The Yellowness Index value, YI, has no unit associatedwith it.9.5 Since organic isocyanates react with atmosphericmoisture, take special precautions in
24、sampling. Usual samplingTABLE 1 CIELAB Round Robin DataL* valuesStandard Material Viscosity Average SrASRBrCRDMineral OilPMDI A 200 mPa s(200 cP)44.93 0.05 0.76 0.15 2.13PMDI B 750 mPa s(750 cP)1.64 0.03 0.26 0.10 0.74Polyol A 475 mPa s(475 cP)99.88 0.03 0.14 0.07 0.40Polyol B 6500 mPa s(6500 cP)96.
25、01 0.11 0.85 0.31 2.37a* valuesStandard Material Viscosity Average SrASRBrCRDMineral OilPMDI A 200 mPa s(200 cP)45.80 0.03 0.26 0.07 0.72PMDI B 750 mPa s(750 cP)9.17 0.12 1.01 0.33 2.82Polyol A 475 mPa s(475 cP)0.13 0.00 0.02 0.01 0.07Polyol B 6500 mPa s( 6500 cP)1.82 0.03 0.26 0.07 0.72b* valuesSta
26、ndard Material Viscosity Average SrASRBrCRDMineral OilPMDI A 200 mPa s(200 cP)72.88 0.09 4.72 0.25 13.22PMDI B 750 mPa s (750 cP) 2.37 0.08 0.44 0.23 1.23Polyol A 475 mPa s(475 cP)0.63 0.01 0.10 0.03 0.29Polyol B 6500 mPa s( 6500 cP)12.32 0.06 1.33 0.16 3.74ASr= within laboratory standard deviation
27、of individual replicates.BSR= between laboratories standard deviation of means of replicates.Cr = within laboratory critical interval between individual replicates (2.8 Sr)repeatability.DR = between laboratory critical interval between means of replicates (2.8 SR)reproducibility.D7133 162methods, ev
28、en when conducted rapidly, can cause contamina-tion of the sample with insoluble urea. Therefore, blanket thesample with dry air or nitrogen at all times. (WarningDiisocyanates are eye, skin and respiratory irritants at concen-trations above the occupational exposure limit (TLV or PEL).Diisocyanates
29、 can cause skin and respiratory sensitization(asthma) in some people. Once sensitized, it is essential to limitfurther exposure to diisocyanates. Use a combination ofengineering controls and personal protective equipment, in-cluding respiratory, skin and eye protection, to prevent over-exposure to d
30、iisocyanates. Consult the product suppliersSafety Data Sheet (SDS) for more detailed information aboutpotential health effects and other specific safety and handlinginstructions for the product)10. Calibration and Standardization10.1 Calibration procedures vary from manufacturer tomanufacturer. They
31、 are important to ensure accurate data.Include the following periodic system verification steps:10.1.1 Wavelength Scale VerificationOne option is to usea didymium filter.10.1.2 Photomeric Scale VerificationThis is to be done inaccordance with manufacturers instructions with a certifiedliquid standar
32、d. An APHA standard is suitable. Linearity isestablished using at least two different standard concentrations.10.1.3 Selection of Instrument Variables10.1.3.1 Select CIE illuminant D65 and 10 standard ob-server.10.1.3.2 Select the total transmission (TTRAN) mode un-less instructed by the manufacture
33、r to use a different mode forthe verification procedure.10.2 Pour mineral oil into a clean cuvette. Ensure that liquidcompletely covers the measurement area and that no airbubbles remain below the meniscus. Follow the manufacturersinstructions to perform the following steps before sampleanalyses and
34、 at least every four hours when samples are beinganalyzed.10.2.1 Full-Scale StandardizationUse a cuvette filled withmineral oil to set the top of the neutral axis scale to 100 bysimulating the case where all light is transmitted through thesample.10.2.2 Zero Scale StandardizationSet the bottom of th
35、eneutral axis scale to 0 by simulating the case where all light isabsorbed by the sample. Block the light beam by replacing thecuvette with an opaque object supplied by the manufacturer.11. Conditioning11.1 Condition liquids for measurement at 23 6 2C unlessotherwise specified by contract or relevan
36、t material specifica-tion.NOTE 2The pure 4,4 isomer of methylene di(phenylisocyanate)(MDI) is a solid at 23C. Condition it for measurement at 50 6 2C.12. Procedure12.1 Sample PreparationPour the sample into a cleancuvette. Ensure that liquid completely covers the measurementarea and that no air bubb
37、les remain below the meniscus.12.2 Selection of Instrument Variables12.2.1 Select CIE illuminant D65 and 10 standard ob-server.12.2.2 Select the total transmission (TTRAN) mode.12.3 Selection of Color Scale and IndexSelect theCIELAB color calculated as defined in Practice E308 and theYellowness Inde
38、x calculated as defined in Practice E313.12.4 Analysis12.4.1 The mineral oil is read as a sample to ensure that theinstrument is set up and reading correctly prior to sampleanalysis. Therefore, measure the cuvette of mineral oil induplicate by following the manufacturers instructions forsample measu
39、rement in TTRAN mode. The average of tworeadings is to meet the following tolerances: L* =100 6 0.1;a*= 0 6 0.1; b*= 0 6 0.1 and YI = 0 6 0.25.12.4.2 Measure the cuvette of the sample in duplicate byfollowing the manufacturers instructions for sample measure-ment in TTRAN mode.12.4.3 Average the res
40、ulting values for L*a*b* and YI.13. Calculation13.1 The instrument software is to automatically calculatethe L*a*b* values in accordance with the equations defined inPractice E308 and theYI value in accordance with the equationin Practice E313.14. Report14.1 The report shall include the following:14
41、.1.1 Date of measurement.14.1.2 Sample description and identification.14.1.3 Any changes from the recommended parameters orconditions (for example, temperature of sample if differentTABLE 2 Yellowness Index Round Robin DataYI valuesStandard Material Viscosity Average SrASRBrCRDMineral OilPolyol A 47
42、5 mPA s(475 cP)1.08 0.01 0.19 0.04 0.52Polyol B 6500 mPa s(6500 cP)21.60 0.10 4.60 0.28 12.88ASr= within laboratory standard deviation of individual replicates.BSR= between laboratories standard deviation of means of replicates.Cr = within laboratory critical interval between individual replicates (
43、2.8 Sr)repeatability.DR = between laboratory critical interval between means of replicates (2.8 SR)reproducibility.D7133 163from 23 6 2C or 50 6 2C for pure MDI, the use of a liquidother than mineral oil for standardization).14.1.4 L*a* b* values and YI value to two significantfigures to the right o
44、f the decimal point.15. Precision and Bias15.1 The precision data presented in this test method arerepresentative of the conditions defined in the standard.However, material preparation and specific test conditions inthe material specification can result in a deviation from theprecision and bias req
45、uiring separate study.15.2 Table 1 is based on a round robin conducted in 2001 inaccordance with Practice E180 involving four materials testedby ten laboratories. For each material, all the samples wereprepared at one source, but the individual specimens wereprepared at the laboratories that tested
46、them. Each test resultwas the average of two individual determinations (replicates).Each laboratory obtained two test results for each material.15.3 Table 2 is based on a limited round robin conducted in2001 involving two materials tested by four laboratories. Foreach material, all the samples were
47、prepared at one source, butthe individual specimens were prepared at the laboratories thattested them. Each test result was the average of two individualdeterminations (replicates). Each laboratory obtained two testresults for each material. (WarningThe explanation of “r”and “R”(15.4 through 15.4.3)
48、 are only intended to present ameaningful way of considering the approximate precision ofthe test method. The data in Table 1 and Table 2 are not to beapplied to acceptance or rejection of materials, as these dataapply only to the materials tested in the round robin and areunlikely to be rigorously
49、representative of other lots,formulations, conditions, materials, or laboratories. Users ofthis test method are to apply the principles outlined in PracticeE691 to generate data specific to their material and laboratory(or between specific laboratories). The principles of 15.4through 15.4.3 would then be valid for such data.)15.4 Precision15.4.1 Repeatability, (r)Comparing two replicates for thesame material, obtained by the same operator, using the sameequipment on the same day. The two replicate results are to bejudged not equivalent
